[cxx-interop] re-enable class-template-variadic.swift test

Author: hyp

Diff for: test/Interop/Cxx/templates/class-template-variadic.swift

@@ -1,11 +1,6 @@
 // RUN: %target-run-simple-swift(-I %S/Inputs -Xfrontend -enable-experimental-cxx-interop)
 //
 // REQUIRES: executable_test
-//
-// We can't yet call member functions correctly on Windows
-// (https://github.com/apple/swift/issues/55575).
-// XFAIL: OS=windows-msvc
-// REQUIRES: fixing-after-30630
 
 import ClassTemplateVariadic
 import StdlibUnittest